There is a constant need for improved materials for medical applications, and particularly in the field of medical tubes and catheter guide devices. An important aspect are the intrinsic frictional properties, for example with respect to metal, for applications in which a wire is to be advanced in a corresponding tube system or, in general terms, for areas in which contact may occur between a surface and metal as part of the medical applications.
In the prior art, high-density polyethylene (HDPE) or polytetrafluoroethylene (PTFE) is used, for example in tubes for medical applications, so as improve the frictional properties. These materials are used in particular as the inner layer of multi-layer materials. Guide catheters having a PTFE inner layer, or tubes made of HDPE, are thus known, for example, from the prior art as protectors for catheters.
As an alternative, the surfaces of tubes are coated in order to reduce the intrinsic material properties, so as to deliberately control the properties hydrophilically or hydrophobically.
A combination comprising a cyclic olefin copolymer (COC) and a catheter is known from WO 2005/044314 A2, for example.
KR 100429660 B1 discloses combinations comprising polyethylene, and more specifically mixtures made of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), and cyclic olefin copolymer as film material, having properties, for example chemical resistance, scratch resistance and flexibility, equal to PVC films, as replacement material for softened PVC (softened PVC films).
The drawback of the existing known solutions is that the intrinsic frictional properties of polymers that are presently used for medical tubing is just barely sufficient, for example for the guide wire friction of inside shafts in RX catheters. So as to prevent excessive force application when inserting the catheter on the guide wire and possible injury to the vascular walls, cardiologists desire catheters that have the lowest possible frictional forces.